156 CORALS 



The following table may be of assistance in identit\'ing 

 the genera of the Stylasterina : 



A. Pores irregularly scattered — 



(a) With styles in the gasteropores : 



(i) Dactylozooids unprotected . Sporadopora. 

 (2) Dactylozooids protected b\' 



grooved spines . . . Errina. 



(b) Without styles Pliobotlinis. 



B. Pores arranged in rows .... Distichopora. 



C. Pores arranged in cyclo-systems — 



{a) \\'ith styles in gasteropores and 



dactylopores Sty last er. 



(b) Without styles : 



(i) Cyclo-systems protected by a 



lamina .... Cryptohdia. 



(2) Cyclo-systems unprotected . Conopora. 



Allopora is now regarded as a sub-genus of Stvlaster, 

 characterised by having relatively thick, blunt, terminal 

 branches, and less prominent calices and ampullae. 



Steganopora and Astylus have only been recorded once 

 from deep water. The former is closely related to Plio- 

 bothrus, the latter to Conopora. 



Labiopora and Spinipora are sub-genera of Errina. 



